Chemical compound applicator for threaded fasteners



Aug. 16, 1966 J. D. ANTHNY 3,266,459

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CHEMICAL COMPOUND APPLICATOR FOR THREADED FASTENERS Filed June 20, 19632 Sheets-$heet 2 INVENTOR.

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United States Patent O 3,266,459 CHEMICAL COMPOUND APPLICATOR FORTHREADED FAS'IENERS Jay l). Anthony, Hobart, Ind., assignor to Screw &Bolt Corporation of America, Pittsburgh, Pa., a corporation ofPennsylvania Filed June 20, 1963, Ser. No. 289,256 8 Claims. (Cl. 118-1)This invention relates to applicators for applying circumferentiallyspaced bands of chemical compounds along the shanks of threadedfasteners, such as screws and bolts.

In my Patent Number 3,061,455 a self-locking bolt is shown that isprovided with spaced areas of chemical compounds which, when mixedtogether, will react and lock the nut and its encircling nut together.This type of bolt is well known and widely used, a preferred form beingone in which two bands of chemical compounds extend lengthwise along theshank of the bolt in circumferentially spaced areas, such as indicatedin FIG. 2 of the patent. The chemical compounds that are used arecapable of polymerizing or copolymerizing when brought together, such asrubber compounds or epoxy resins, all as explained in the patent. Theparticular compounds used form no part of the present invention, whichis directed solely to lapparauts for applying the compounds 'to thefasteners.

It therefore is among the objects of this invention to provide means bywhich reactive compounds can be applied to the threaded shank of afastener rapidly, inexpensively and easily.

In accordance with this invention a housing is provided with a straightpassage through it having a rear end and a front end. Slidably mountedin this passage is a piston that projects from its rear end. Means areconnected with the rear end of the piston yto position its front end inthe front end of the passage to close it. The housing is provided atopposite sides of the passage adjacent the front end thereof withchambers extending along the passage and opening into it. The innersides of the chambers are spaced apart and normally are closed by thepiston. The housing has an inlet por-t for each chamber, and means areprovided for delivering a different chemical compound to each port underpressure to maintain the chambers full of those compounds. The piston ismovable rearwardly when its front end is engaged by a fastener shank inline with it and having a diameter no lgreater than the diameter of thepiston. Consequently the fastener can enter the passage to receivecoatings of the chemical compounds in two spaced bands extendinglengthwise of the fastener. When the piston is moved forward again, thecoated fastener is ejected from the passage.

The preferred embodiment of the invention is illustrated in theaccompanying drawings, in which FIG. 1 is a side view of my applicator,mostly in vertical section;

FIG. 2 is a similar view, showing a bolt being coated;

FIG. 3 is an enlarged vertical `.section through the coating housingtaken on the line III--III of FIG. 2 but with the bolt absent;

FIG. 4 is an enlarged horizontal section taken on the line IV--IV ofFIG. 2;

FIG. 5 is an enlarged horizontal section taken on the line V-V of FIG.2, with the bolt removed; and

FIG. 6 is an enlarged side view of a bolt coated by my applicator.

Referring to the drawings, the applicator housing includes a metal block1, usually cylindrical, that is provided with an axial passage 2extending through it from end to end. This passage has a diameter greatenough to receive the threaded fasteners that are to be coated,preferably with a slight clearance around them. Although the block canbe used on its sides, it is more satisfactory in an upright position asshown. Slidably mounted in the block passage is a piston 3 that is in`the form of a rod long enough to extend entirely through the block andproject from its rear or upper end. Assuming that only two chemicalcompounds are to be applied with this device, the lower part of theblock is provided at opposite sides of its central passage with a pairof vertical chambers 4 and 5, preferably extending upwardly from thelower or front face of the block. The inner sides of the chambers openinto the central passage, while their outer sides are open at theperiphery of the block. When the piston is in its lower position asshown in FIG. l, with its front end closing the front or lower end ofthe passage, the inner sides of the two chambers are spaced apart by thepiston and normally are closed by it.

To close the bottoms of the block chambers, a circular bottom plate 7 isfastened by screws 8 to the bottom of the block. This plate projectsradially from the block and for-ms a retaining member which supports asleeve 9 that snugly encircles the block and extends a s'hort distanceup above the top of the chambers. The sleeve closes the outer sides ofthe chambers. It is held down tightly against the bottom plate by meansof a nut 10 screwed on the threaded upper end of the block andpreferably pressing a yoke 11 down against the sleeve. The nut, yoke andbottom plate also form parts of the applicator housing. The yoke issupported by a bracket 12 that is attached to a suitable support forsupporting the housing. The sleeve is provided at the outer side of eachchamber with an inlet port 13, in which a tube 14 is screwed, theopposite end of the tube being connected to suitable means (not shown)for delivering a plastic chemical compound 15 or 16 to the adjoiningchamber under constant pressure. When the piston is in its lowerposition it prevents the compounds in the two chambers from mixing.

The applicator may be used by aligning a screw or bolt 1S with the lowerend of the lowered piston as shown in FIG. 1, and then simply raisingthe threaded end of the bolt to push the piston upwardly in passage 2 sothat the threaded shank of the bolt takes the place of the pistonbetween the two chambers `as shown in FIG. 2. The opposite sides of thebolt therefore are exposed directly to the chemical compounds in the twochambers, and the pressure behind the compounds forces them forwardbetween the screw threads so that when the bolt is removed from thehousing its threaded shank is provided with a pair of circumferentiallyspaced bands 15a and 16a of the chemical compounds extending lengthwisealong it,

as shown in FIG. 6. The bolt is not left in the housing long enough forthe viscous compounds to ilow laterally around it and meet. As the boltis removed, the piston is lowered with it to keep the two compoundsapart. EX- cess plastic may be wiped from the bolt as it is withdrawnfrom the housing, by means of a resilient wiping ring 19 `mounted in arecess 20 (FIGS. 3 and 5) in the bottom of block 1 around the lower endof the central passage. The ring is supported by the bottom plate andsnugly engages the bolt. The chemical compounds can be kept away fromthe end threads of the bolt, so that a nut can be started on the boltmore easily, by providing the front end of the piston with a largerecess 21 that receives the end portion of the bolt and thereby coversits threads. This recess also centers the bolt in passage 2.

For easier operation of the applicator and best results it is desirablethat the piston be :raised in the housing passage, not by the pressureof the bolt against it, but by power means connected with the upper endof lthe piston. As shown in FIGS. 1 and 2, such means may include adouble acting air cylinder 23 rigidly mounted above piston 3 andcontaining a piston of its own which has ,la downwardly extending pistonIrod 24 suitably conneoted to the upper end of the piston below it. Air

under pressure can be admi-tted and exhausted from the opposite ends ofthe cylinder by means of electric valves and 26, the lower one of whichis opened to air pressure automatically or by a suitable manualoperation when the bolt is engaged with the lower end of the piston. Atthe same time, the upper valve exhausts to atmosphere. The piston thenis slowly raised or retracted in the housing by piston rod 24 as theoperator maintains the bolt in contact with its lower end. When thepiston has risen to the desired height, as shown in FIG. 2, it may tripa limit switch 27 that controls the upper valve 26 to admit air pressureto the upper end of the cylinder tio push the piston back down again,while the lower valve connects the lower end of the cylinder with theatmosphere.

Preferably, piston 3 is provided with an axial bore in which a small rod30 is slidably mounted. 'The upper end of this rod projects above thepiston and the lower end carries a head 31 in recess 21. When a bolt isinserted in this recess while the piston is in its lower position, thehead and rod are moved up in the piston so that the upper end of the rodwill close an electric switch 32 rigidly mounted inside of a switchhousing 33 screwed onto the upper end of the piston. This housing issupporte-d by pis-ton rod 24 from the cylinder above it. The switch isconnected with the lower valve to cause it to admit air pressure to thelower end of the cylinder, whereby the simple step of inserting the boltin recess 21 sets the applicator in operation.

I claim:

1. An applicator for applying a pair of circumferentially spaced bandsof chemical compounds lengthwise along the shank `of a fastener, saidapplicator comprising a ,housing provided with a straight passagetherethrough having a .rear end and a front end, a piston slidablymounted in the passage and projecting from said rear end, meansoperatively connected with the rear end of the piston Afor normallypositioning its 'front end in the r-ont end Iof the passage to close it,the housing being provided at opposite sides of said passage adjacentthe front end of the passage with chambers extending along the passageand opening into it, the inner sides of said chambers being spaced apartand normally being closed by the piston, the housing having an inletport for each chamber, and means ttor delivering a different chemicalcompound Ito each port under pressure to maintain said chambers full ofthe compounds, the piston being movable rearwardly when its front end isengaged by an axially aligned fastener shank having a diameter nogreater than the diameter of the piston, whereby the fastener can entersaid passage to receive coatings of said compounds in two spaced bandsextending lengthwise of the fastener.

2. An applicator according to claim 1, including a resilient wiping ringmounted in the front end of said passage and having an inner diameterslightly smal-ler than the diameter of the passage.

3. An applicator according to claim 1, in which the front end 'of saidpiston is provided with a large recess adapted to receive the tip of theshank of a lfastener.

4. An applicator according to claim l, in which said 'housing includes ablock provided with said passage and chambers, and a sleeve surroundingsaid block and closing the outer sides of the chambers, the sleeve beingprovided with said inlet ports.

5. An applicator accor-ding to claim 4, including a retaining membersecured to the front end of said block and engaged by the front end ofsaid sleeve, the block having an externally :threaded portion projectingfrom the lrear end of the sleeve, and a nut screwed onto said threadedportion for pressing the sleeve against said retaining member.

6. An applicator according to claim l, including fluid operated pressuremeans operatively connected with the piston, a normally closed valvecontrolling delivery of pressure fluid to said fluid pressure operatedmeans to retract the piston, and means for opening said valve when thetip of a fastener is brought intro engagement with the front end of thepiston.

7. An applicator according to claim 6, including a normal-ly closedelectrically operated valve controlling delivery of pressure fluid tosaid uid pressure operated means to return said piston tfrom itsretracted position, an electric limit switch connected with saidlast-mentioned valve, and means movable rearwardly with the piston foroperating said switch.

S. An applicator according to claim 1, in which said piston is providedwith an axial bore therethrough and with a large recess in its frontend, said applicator inclu-ding a push rod slidably mounted in said boreand projecting from the opposite ends thereof, a head on the end of said.rod in said recess, uid pressure operated means operatively connectedwith the piston, a normally closed electrically operated valvecontnolling delivery of press-ure uid to said fluid pressure operatedmeans to retract the piston, and an electric switch connected with saidvalve for opening it and operated by the rea'r end of the rod when therod is pushed rearwardly by the tip of a fastener inserted in saidpiston recess and pushed `against said head.

References Cited by the Examiner UNlTED STATES PATENTS 924,452 6/1909Graham 118-404 CHARLES A. WILLMUTH, Primary Examiner.

1. AN APPLICATOR FOR APPLYING A PAIR OF CIRCUMFERENTIALLY SPACED BANDSOF CHEMICAL COMPOUNDS LENGTHWISE ALONG THE SHANK OF A FASTENER, SAIDAPPLICATOR COMPRISING A HOUSING PROVIDED WITH A STRAIGHT PASSAGETHERETHROUGH HAVING A REAR END AND A FRONT END, A PISTON SLIDABLYMOUNTED IN THE PASSAGE AND PROJECTING FROM SAID REAR END, MEANSOPERATIVELY CONNECTED WITH THE REAR END OF THE PISTON FOR NORMALLYPOSITIONING ITS FRONT END IN THE FRONT END OF THE PASSAGE TO CLOSE IT,THE HOUSING BEING PROVIDED AT OPPOSITE SIDES OF SAID PASSAGE ADJACENTTHE FRONT END OF THE PASSAGE WITH CHAMBERS EXTENDING ALONG THE PASSAGEAND OPENING INTO IT, THE INNER SIDES OF SAID CHAMBERS BEING SPACED APARTAND NORMALLY BEING CLOSED BY THE PISTON, THE HOUSING HAVING AN INLETPORT FOR EACH CHAMBER, AND MEANS FOR DELIVERING A DIFFERENT CHEMICALCOMPOUND TO EACH PORT UNDER PRESSURE TO MAINTAIN SAID CHAMBERS FULL OFTHE COMPOUNDS, THE PISTON BEING MOVABLE REARWARDLY WHEN ITS FRONT END ISENGAGED BY AN AXIALLY ALIGNED FASTENER SHANK HAVING A DIAMETER NOGREATER THAN THE DIAMETER OF THE PISTON, WHEREBY THE FASTENER CAN ENTERSAID PASSAGE TO RECIEVE COATINGS OF SAID COMPOUNDS IN TWO SPACED BANDSEXTENDING LENGTHWISE OF THE FASTENER.